I Didn't Know That: Diamonds
Learn how diamonds do more than just shine as flashy bling.
Transcript
RICHARD AMBROSE: If you thought the sparkle on your finger was the only diamond in your life then think again because industrial diamonds are in use all around us. Even the tiles in your toilet were probably cut with a diamond blade.
Top quality naturally occurring diamonds cost thousands of pounds, but this entire dish of synthetically grown diamonds costs around 50 pounds, in fact the majority of diamonds used in industry are grown synthetically.
RICHARD AMBROSE: Man made diamonds were first created in the early 1950's using high temperatures and high pressure and the basic ingredient carbon. In fact given the right conditions you can make diamonds out of any type of carbon including burnt toast. Once the bread is truly burnt its ground down and squeezed into a mould, then a special machine takes it to a pressure 60 thousand times greater than our atmosphere at which point the carbon naturally becomes diamond.
RICHARD AMBROSE: And what about the results, well your other half won't be too impressed if you propose with one because two bits of burnt toast won't produce a diamond that's visible to the human eye, but you can see them in this photograph with a 10 thousand times magnification. Many diamonds are made this way to be used as abrasives, saw blades and drill bits are coated with them, several face exfoliants contain diamonds and some eye surgeons use diamond knifes. It's in so many things because it's very very hard.
RICHARD AMBROSE: Hardness is measured on what's called the moh's scale; at the bottom of the scale we have soft things like talc, mid way along materials like steel, but at the top of the scale the hardest naturally occurring thing known to mankind diamond.
Different types of diamond are being developed which could see us using them in a whole new way. They are made with low pressure; methane and hydrogen are taken to just 1/100th of the pressure our atmosphere and heated until they are as hot as the surface of the sun.
RICHARD AMBROSE: This smashes the molecules apart and eventually produces diamonds. The results are tiny crystals which can be formed into some of the most amazing shapes, long thin wires and large flat plates that can be highly polished until they're see through like glass. This disc of synthetic diamond is perfectly transparent and so tough that one space craft which travelled to Venus had its windows made of it.
RICHARD AMBROSE: We've got some ice here, we're gonna demonstrate one of the lesser known but very remarkable properties of diamond. Chris how does it work?
CHRIS WORD: Well basically diamond has an incredibly high thermal conductivity, it's five times higher than copper. So what I want you to do is hold that piece of diamond and hold a copper coin there.
RICHARD AMBROSE: OK yes.
CHRIS WORT: And then connect them together onto an ice cube and just tell me which one gets cold quickest.
RICHARD AMBROSE: Within seconds the heat from my hand alone quickly transmits into the diamond disc and cuts the ice like butter. The amazing thing is the diamond edge is in fact blunt.
RICHARD AMBROSE: That's amazing that really is amazing. Diamond can also be doped with the element boron to conduct electricity, the fact it can do this and that it can dissipate heat quickly means it likely to be used in electrical devices in the future to give us fast speeds with small chips, giving it yet another use in our lives.